Method of manufacturing secondary-battery plates.



UNITED STATES AT'ENT OFFICE.

CHARLES HERBERT TAYLOR,

OF EAST CLEVELAND, OHIO.

METHOD OFMANUFACTURING SECONDARY-BATTERY PLATES.

SPECIFICATION forming part of Letters Patent 'No. 708,694, datedSeptember 9, 1902.

Application filed December '7, 1901.

To all whom it may concern:

Be it known that I, GEORGE H. CHRISTIAN, a citizen of the United States,and a resident of Cleveland, county of Ouyahoga, and State of Ohio,haveinvented a newand useful Improvement in Methods of Manufacturing Platesfor Secondary Batteries, of which the following is a specification, theprinciple of the invention being herein explained and the best mode inwhich I have contemplated applying that principle, so as to distinguishit from other inventions.

My invention relates to the manufacture of secondary batteries, and isparticularly di- I 5 rected to the preparation of the spongy-leadelement of such batteries an electrolyte containing a compound of anorganic reducing agent, as wherein it is necessary to convert the leadoxid previously formed or existing into spongy lead.

The following description sets forth in detail one mode of carrying outthe invention, such disclosed mode constituting but one of various waysin which the principle of the invention may be used. In one method ofcarrying out such process at present practiced grooved lead plates aresuspended as electrodes in an electrolytic bath, the electrolyte inwhich is composed of a solution of sulfuric and nitric acids andammonium hydrate and then electrolyzed. The resultant electrolyticaction effects the dissolution of the lead of the cathode-plates and theformation of a deposit of lead peroxid upon the 5 anode-plates. Theseperoxid plates are next suspended as electrodes in an electrolytic bathcontaining an electrolyte composed of dilute sulfuric acid and thenelectrolyzed, the electrolytic action converting the peroxid upon thenegative electrode into spongy lead.

This process of deoxidation is slow and tedious, occupying aboutseventeen days for the size of plate ordinarily used, and must beconducted with care as to the quality of the our- 5 rent used, animproper use of the current or the use of an improper current reducingthe efficiency of the resulting plate. In a second method at presentpracticed plates provided with litharge and red lead are respectivelycaused to constitute the cathode and anode of an electrolytic cellhaving an electrolyte consisting of dilute sulfuric acid. The re- SerialNo. 85,073. o specimens.)

sultant electrolysis deoxidizes the litharge to form spongy lead andchanges the red lead to lead peroxid. Instead of conducting suchdeoxidation in either of the above processes in an electrolytecontaining sulfuric acid I substitute therefor a solution of a compoundof an organic acid with an alkaline earth, such as oxalate of potassium,oxalate of sodium, &c. The oxalate is preferably prepared in solutionwith Water. The peroxid plates are suspended in such electrolyte, so

as to form the negative electrodes, plain lead plates being used for thepositive electrodes. Upon the passage of the current, which is Ipreferably of about one half ampere per square inch of plate-surface,the peroxid is rapidly deoxidized, forming spongy lead, and

in the ordinary five-by-seven-inch plates is completed in about seven totwelve hours. The solution is maintained at the abovenamed strengthduring the electrolytic action by continually adding as is required theoxalate to replace that decomposed by the electrolysis. The plain leadsheets should be about one thirty-second of an inch thickness, of thesame Width as the peroxid plates, and separated from the latter by hard-rubber strips or bars about one-eighth inch in diameter or one-eighthinch by one-fourth inch to prevent short-circuiting. The spongy leadplates are then removed from the electrolytic bath, immersed in a bathof running water, and permitted to remain therein for about twelve hoursin order to thoroughly remove the oxalate and other substances remainingin the pores of the lead. The spongylead plates are now ready for use inthe secondary battery. By this means I have found that spongy-leadplates having superior physical and electrical qualities, with less lossof active material, are produced, a Wider varia tion in the qualities ofthe current used being permitted, such plates having a greater 5electrical capacity per pound of lead than plates heretoforemanufactured by other methods.

The results obtained show a marked economical gain in the plateefficiency where my invention is employed in connection with red lead,litharge, and all other compounds of lead and oxygen other than peroxid.

Other modes of applying the principle of my invention may be employedinstead of the one explained, change being made as regards the processherein disclosed, provided the steps stated by any one of the followingclaims or the equivalent of such stated steps be employed.

I therefore particularly point out and distinctly claim as myinvention 1. In the process of manufacturing plates for secondarybatteries, the step which consists in electrolytically reducing an oxidof lead in an electrolytic cell having an electrolyte containing acompound of an organic reducingagent.

2. In the process of manufacturing plates for secondary batteries, thestep which consists in electrolytically reducing an oxid of lead in anelectrolytic cell having an electrolyte containing an organic-acidcompound.

3. In the process of manufacturing plates for secondary batteries, thestep which consists in electrolytically reducing an oXid of lead at thecathode of an electrolytic cell having an electrolyte containing anorganic-acid compound.

4:. The process of converting an oxid of lead into spongy lead, whichconsists in electrolytically reducing such oxid in an electrolytic cellhaving an electrolyte containing a compound of an organic reducingagent.

5. The process of converting an oxid of lead into spongy lead, whichconsists in electrolytically reducing such oxid in an electrolytic cellhaving an electrolyte containing an organic-acid compound.

(5. The process of converting an oxid of lead into spongy lead, whichconsists in electrolytically reducing such oxid in an electrolytic cellhaving an electrolyte containing an OX- alic-acid compound.

7. The process of manufacturing spongylead plates for secondarybatteries, which consists in electrolytically reducing an oxid of leadin an electrolytic bath having an electrolyte containing a compound ofan organic reducing agent and strengthening such electrolyteperiodically by addition of such compound as reduction progresses.

8. The process of manufacturing spongylead plates for secondarybatteries which consists in electrolytically reducing an oXid of lead inan electrolytic bath having anelectrolyte containing an organic-acidcompound and strengthening such electrolyte periodically by addition ofsuch compound as reduction progresses.

9. The process of manufacturing spongylead plates for secondarybatteries which con sists in electrolytically reducing oxid of lead inan electrolytic bath having an electrolyte containingoxalic-acidcompound and strengthening such electrolyte periodically by addition ofsuch compound as reduction progresses.

10. The process of manufacturing spongy lead, which consists inelectrolytically red using lead peroxid in an electrolytic cell havingan electrolyte containing a compound of an organic reducing agent.

11. The process of manufacturing spongy lead, which consists inelectrolytically reducing lead peroxid in an electrolytic cell having anelectrolyte containing an organic-acid compound.

12. The process of manufacturing spongy lead, which consists inelectrolytically reducing lead peroxid in an electrolytic cell having anelectrolyte containing an oxalic-acid compound.

13. The step in the process of manufacturing secondary batteries, whichconsists in the deoxidation of an oxid of lead by means of electrolysisin a bath containing a compound of an organic reducing agent.

14.. The step in the process of manufacturing secondary batteries, whichconsists in the deoxidation of an oxid of lead by means of electrolysisin a bath containing an organicacid compound.

15. The step in the process of manufacturing secondary batteries, whichconsists in the deoxidation of an oxid of lead by means of electrolysisin a bath containing an oxalicacid compound.

16. The process of converting an oxid of lead into spongy lead whichconsists in electrolytically reducing such oXid in an electrolytic cellhaving an electrolyte containing compound of an organic acid and analkaline earth.

17. The process of converting an oxid of lead into spongy lead, whichconsists in electrolytically reducing such oxid in an electrolytic cellhaving an electrolyte containing a compound of an organic reducing agentand an alkaline earth.

18. The process of converting an oXid of lead into spongy lead, whichconsists in electrolytically reducing such oxid in an electrolytic cellhaving an electrolyte containing a solution of a compound of an organicreducing agent and an alkaline earth.

19. The process of converting an oxid of lead into spongy lead, whichconsists in electrolytically reducing such oxid in an electrolytic cellhaving an electrolyte containing a solution of a compound of an organicacid and an alkaline earth.

520. The process of converting an oxid of lead into spongy lead, whichconsists in electrolytically reducing such maid in an electrolytic cellhaving an electrolyte containing a solution of a compound of oxalic acidand an alkaline earth.

Signed by me this 2d day of December, 1901.

GEO. II. CHRISTIAN.

Attest:

WM. 11. TRICKER, ADELE TRICKER.

